WordNet sense 1 (a collection containing a variety of sorts of things):

assortment, miscellanea, miscellany, mixture, motley, potpourri, smorgasbord, salmagundi, mixed bag

WordNet sense 2 (a show consisting of a series of short unrelated performances):

variety show

WordNet sense 3 (a category of things distinguished by some common characteristic or quality):

form, kind, sort

WordNet sense 4 (a difference that is usually pleasant):

change

WordNet sense 5 (noticeable heterogeneity):

diverseness, diversity, multifariousness